fix: correct openclaw config set command syntax

- Move --json flag to correct position (before value)
- Add explicit encoding and error handling

install.mjs

@@ -95,14 +95,13 @@ function getOpenclawConfig(pathKey, defaultValue = undefined) {
 }
 
 function setOpenclawConfig(pathKey, value) {
-  execSync(`openclaw config set ${pathKey} '${JSON.stringify(value)}' --json`, {
-    cwd: __dirname
-  });
+  const cmd = `openclaw config set ${pathKey} --json '${JSON.stringify(value)}'`;
+  execSync(cmd, { cwd: __dirname, encoding: 'utf8' });
 }
 
 function unsetOpenclawConfig(pathKey) {
   try {
-    execSync(`openclaw config unset ${pathKey}`, { cwd: __dirname });
+    execSync(`openclaw config unset ${pathKey}`, { cwd: __dirname, encoding: 'utf8' });
   } catch {
     // Ignore errors
   }